MECHANICS REVIEW #2 WITH
QUESTIONS AND 100% CORRECT
ANSWERS { GRADED A+}
A contractor wants to raise the car speed from 100FPM to 125FPM. It
currently has a 12" sheave, what size sheave is required? - ✔✔15"
Diam=12, 12"/4=3, 25FPM= 3"
An MOV(metal oxide varistor) burns out. You replace it, but cannot
read Voltage or Resistance. What should you do? - ✔✔Replace it with
a larger MOV. (630)
On a Ward-Leonard circuit, the break is set, but the motor is trying to
slip through the break. What circuit is the issue? - ✔✔Suicide Circuit
(425)
,You have an old DC motor and you are adding an SCR Drive. What do
you do with the interpoles? - ✔✔Leave the interpoles alone (425) note:
When adding an SCR Drive to the generator, the series loop is removed,
as are the three resistors. Everything else stays the same.
A hydro runs up with no load, but does not run up with a full load. What
is the issue? - ✔✔The relief valve is set to low (805)
Runby for a 1:1 car hits the CWT buffer 4" below the top landing. The
CWT runby should be set at 18". How much should the ropes be
shortened? - ✔✔22" and for a 2:1 with the same issue? 44"
You need to work on a freight door retiring cam. You LOTO the
mainline disconnect, but there is still power to the cam. What circuit is
still Hot? - ✔✔Mainline disconnect
The contractor request that the vertical center of the rack and pinion
hoist be moved. How is this accomplished? - ✔✔Adjust tie downs/wall
ties
, Working pressure on a Hydro is 400 PSI. What is the correct relief valve
setting? - ✔✔600 PSI max. (805) 400psi x 150%= 600psi
What must first be installed on a false car before operation? -
✔✔Safeties (110) nite: handrails and buffers also required
There is slight arcing at the brush and commutator. What actions must
be taken? - ✔✔None. (430) heavy arcing is due to light brush pressure,
mechanical wear indicates heavy brush pressure
If rigging gear is ropes 3:1 and a beam clamp is used to lift a 6000lb
load. What is the beam capacity requirement? - ✔✔18000lb min. Note:
a beams capacity is cut in half by the beam clamp. (210) note: when
rigging all blocks, rope and clamps will be equal to the lowest load
rating capacity.
How much resistance is normally measured across a normally closed
switch? - ✔✔1.2 ohm
A car traveling in the hoistway always stops at the same point and blows
a fuse. What is the problem? - ✔✔Traveling cable has a cut or short
QUESTIONS AND 100% CORRECT
ANSWERS { GRADED A+}
A contractor wants to raise the car speed from 100FPM to 125FPM. It
currently has a 12" sheave, what size sheave is required? - ✔✔15"
Diam=12, 12"/4=3, 25FPM= 3"
An MOV(metal oxide varistor) burns out. You replace it, but cannot
read Voltage or Resistance. What should you do? - ✔✔Replace it with
a larger MOV. (630)
On a Ward-Leonard circuit, the break is set, but the motor is trying to
slip through the break. What circuit is the issue? - ✔✔Suicide Circuit
(425)
,You have an old DC motor and you are adding an SCR Drive. What do
you do with the interpoles? - ✔✔Leave the interpoles alone (425) note:
When adding an SCR Drive to the generator, the series loop is removed,
as are the three resistors. Everything else stays the same.
A hydro runs up with no load, but does not run up with a full load. What
is the issue? - ✔✔The relief valve is set to low (805)
Runby for a 1:1 car hits the CWT buffer 4" below the top landing. The
CWT runby should be set at 18". How much should the ropes be
shortened? - ✔✔22" and for a 2:1 with the same issue? 44"
You need to work on a freight door retiring cam. You LOTO the
mainline disconnect, but there is still power to the cam. What circuit is
still Hot? - ✔✔Mainline disconnect
The contractor request that the vertical center of the rack and pinion
hoist be moved. How is this accomplished? - ✔✔Adjust tie downs/wall
ties
, Working pressure on a Hydro is 400 PSI. What is the correct relief valve
setting? - ✔✔600 PSI max. (805) 400psi x 150%= 600psi
What must first be installed on a false car before operation? -
✔✔Safeties (110) nite: handrails and buffers also required
There is slight arcing at the brush and commutator. What actions must
be taken? - ✔✔None. (430) heavy arcing is due to light brush pressure,
mechanical wear indicates heavy brush pressure
If rigging gear is ropes 3:1 and a beam clamp is used to lift a 6000lb
load. What is the beam capacity requirement? - ✔✔18000lb min. Note:
a beams capacity is cut in half by the beam clamp. (210) note: when
rigging all blocks, rope and clamps will be equal to the lowest load
rating capacity.
How much resistance is normally measured across a normally closed
switch? - ✔✔1.2 ohm
A car traveling in the hoistway always stops at the same point and blows
a fuse. What is the problem? - ✔✔Traveling cable has a cut or short
